Add cargo-hack to CI to check crate features

[macladson]

Issue Addressed

#8926

Proposed Changes

Add a step to CI which runs cargo check across all combinations of features for certain crates using cargo-hack

Additional Info

I have only implemented checks for eth2 and types since these are our most "user-facing" crates but we can consider other candidates as well.

The number of checks it makes scales at $2^N$ where N = number of features. So adding a single new feature effectively doubles the number of checks required. So when adding more features we should try to identify which features we can exclude if possible.

[macladson]

Note that I am excluding arbitrary-fuzz (since it is merely an alias of arbitrary) and portable (since it just enables a bls feature which should have no impact on our own compilation).

[macladson]

We could also consider testing even more crates but using --depth 2 to only test pairs of features. This would probably cover the vast majority of possible feature conflict scenarios (this is what tokio does)

[chong-he]

Looks good. I have tested removing #[cfg(feature = "events")] in the eth2 crates and it will error. Just one comment below.

[chong-he]

Instead of having a new check at the top-level (which makes the total check increases), I am wondering if we could combine all dependencies-related checks (cargo-udeps, cargo-sort and the current cargo-hack) into one top-level check, and then have these 3 cargo checks under it. We can name the top-level check something like "dependency-check". That will also reduce some boilerplate when defining the name etc required for a new top-level check. Just my 2 cents

[mergify]

Merge Queue Status

• ✅ Entered queue — 2026-04-07 05:53 UTC · Rule: default
• ✅ Checks passed · on draft merge queue: embarking unstable (9f0696f) and #8927 together #9103
• ✅ Merged — 2026-04-07 06:23 UTC · at 0b6bb96f390ccc25fcce567336854d49beaba5e8

This pull request spent 29 minutes 28 seconds in the queue, including 27 minutes 8 seconds running CI.

Required conditions to merge

• #approved-reviews-by >= 1 [🛡 GitHub branch protection]
  • Add cargo-hack to CI to check crate features #8927
• #changes-requested-reviews-by = 0 [🛡 GitHub branch protection]
  • Add cargo-hack to CI to check crate features #8927
• check-success=local-testnet-success
• check-success=test-suite-success